The invention relates to a method for the recovery of materials, particularly from construction site wastes, as well as to a system for implementing the method.
According to a reference in German Patent No. 3,248,493, the construction industry encounters, in addition to its classical demolition rubble, a waste material composed of the classical rubble of sand, soil, rocks and concrete remnants, as well as mixed rubble containing a large percentage of reusable substances such as wood, metal, textiles, paper, plastics or the like. This mixed rubble encountered during the reconstruction of buildings has in the past been sent in large quantities to trash dumps with the result that the dumps are filled up quickly. As stated in the cited patent, it is also desirable to separate such mixed rubble or mixed waste into its components in order to be able, in particular, to recycle the valuable materials and simultaneously reduce the amount stored in dumps. It would therefore be desirable to separate the mixed rubble from construction site wastes in such a way that it is divided into its essential components that can be recycled.
The above-cited U.S. Pat. No. 3,248,493 discloses, as a solution of this problem, a method as well as a system for implementing the method in which a plurality of process steps including automatic and manual sorting are connected in series. For example, the following assemblies are connected in series: preliminary screen, bunker, first handling station, shears, iron selector, first screening drum, non-ferrous selector, second handling station, second screening drum, etc. This plurality of individual, automatic or manual processing stations are connected with one another by means of conveyor belts. The final fractions obtained at the end are then generally again transported by means of conveyor belts to separate bunkers or onto a stockpile.
Such systems are spread out over a very large area, with the connection between the individual processing stations being effected by means of conveyor belts. Such systems are therefore feasible to erect only at an exposed location since they usually also involve a considerable stress on the environment, particularly with respect to noise and dust. The construction site wastes must therefore often be transported over long distances to these special systems, which also involves costs and effort. Moreover, the generally employed conveyor belts to connect the individual processing stations are very expensive and susceptible to damage from such complicated construction site wastes. The final fractions are then transported by means of additional conveyors to stockpiles or in containers.